Centrifugal pumps



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4 Sheets-Sheet 1 Filed Sept. 14, 1956 ///f/V-r@ John C/ar l (deceased)5)/ Jane arr Chr@ Jan. 13, 1959 J. CLARK 2,868,133

CENTRIFUGAL PUMPS Filed Sept. 14, 1956 4 Sheets-Sheet 2 jpl/p7] Y] AttorzeyS 4 Sheets-Sheet 3 Filed Septy 14, 1956 a m 0 M a ma Z 6 M f u w/p dM /ac r rib mmf arf/m r ZJ ,.2 wm Jaw Att rneys Jan. 13, 1959 J, @ARK2,868,133

CENTRIFUGAL PUMPS Filed Sept. 145.1956 4 Sheets-Sheet 4 #VVE/V70@ JohnCMPK (deceased) om e ys United States Patent() CENTRIFUGAL PUMPS JohnClark, deceased, late of Rutherglen, Scotland, by Jane B. Clark andMargaret S. L. Clark, Rutherglen, and Helen MacMurchy, Strathaven,Scotland, executrices, assignors to Jane Barr Clark, Rutherglen,Lanarkshire, Great Britain Application September 14, 1956, Serial No.610,026

2 Claims. (Cl. 103-87) This invention has reference to centrifugal pumpsof the kind provided with a conical impeller having spiral vanes whichform therebetween ducts each preferably of substantially uniform crosssectional area throughout its length and non-rotatable spiral vaneswhich receive the liquid delivered thereto by the impeller for onwarddelivery to the discharge outlet of the pump.

The present invention has for its object to provide a pump of the kindset forth of high elllciency, reliable in operation and simple inconstruction.

According to the present invention in a pump of the kind set forth theimpeller is fast on the shaft of an electric motor enclosed in acylindrical casing constituting the pump body, said casing having lixedspiral ducts and communicating therewith an annular axial passage whichdelivers the liquid received from the impeller to the pump dischargeoutlet.

The invention further consists in a pump as set forth in the precedingparagraph wherein the motor and its shaft are sealed. .against contactwith liquid flowing through the pump.

The pump may be provided with a flanged impeller cover secured to thecylindrical pump body, an inlet branch secured to the said cover and anon-rotatable floating sealing ring located between said cover and inletbranch and arranged to bear on an external flange of the impeller and anannular bearing face of the inlet branch, the construction being suchthat the ring is held to bear on the said flange and bearing face by thepressure of liquid which may leak thereto or by the minus pressure whichmay exist in the inlet branch.

One construction of pump in accordance with the invention will now bedescribed, by way of example, with reference to the annexed drawingswherein:

Figure l is a sectional elevation of the improved pump;

Figure 2 is a sectional elevation of the impeller;

Figure 3 is a section on the line 3 3 of Figure 2;

Figure 4 is an elevation partly in section of the right hand end of thepump body showing a number of the fixed vanes;

Figure 5 is an end view thereof looking to the left with the pump bodycut away to show the vanes; and

Figure 6 is a section on the line 8-8 of Figure l.

The improved pump as shown in the drawings is provided with a pump bodyin the form of a cylinder or casing 10 with external flanges 11 at itsends and provided with supporting feet 12. The cylinder is formed of anouter and an inner shell or shroud 13 and 14 respectively which formtherebetween an annular axially-extending passage 15 which at its righthand end curves inwardly. The shells are maintained in spacedrelationship by fixed longitudinally-extending vanes 15a and also bymeans of a series of integral bridge pieces 21 located at the left handend. Said vanes 15a and bridge pieces form therebetween a series ofcircumferentially extending gaps 22 (see Figure 6).

Provided between the curved ends of the outer and 2,868,133 PatentedJan. 13, 1959 Nce inner shells 13 and 14 and also extending partly alongthe annular passage is a series of fixed spiral vanes 17 integral withaxial vanes 17a said vanes forming therebetween spiral ducts 18 andaxial ducts 18a.

The cylinder at the end provided with the fixed-spiral vanes is providedwith an inwardly-turned flange 19 which supports a housing 20 in whichis fitted a combined journal and thrust anti-friction bearing 20a.

To the other end ofthe cylinder is secured a flanged discharge member 23which supports a housing 24 by means of annular support 23a castintegral with the discharge member 23 and forming therewith an annularpassage 2311. The annular support 23a is connected to the dischargemember 23 by means of a series of bridge pieces 23e forming therebetweena series of circumferentiallydisposed passages which register with thegaps 22. In said housing 24 is fitted a further combined journal andthrust anti-friction bearing 25. Journalled in the two bearings is ashaft 26 which carries the rotor 27 of an electric motor, the stator 28of which fits snugly within the cylinder to which it is anchored. Thehousing 24 embodies a cover plate 29 by which the passage of water tothe shaft and its motor is prevented.

The stator is located within the cylinder by means of screws which passthrough holes in the outer and inner shells and through holes 15b in thevanes 15a.

Fast on the right hand end of the shaft is the impeller formed of outerand inner cone-like shrouds or shells 30 and 31 and spiral vanes 32between the shells, the vanes forming with the shells a series of spiralducts 33 each, in preference, of substantially uniform cross sectionalarea throughout its length, see particularly Figures 2 and 3. That is,each of said spiral ducts widens in a circumferential direction anddiminishes in depth as it approaches the fixed vanes to maintainuniformity of cross sectional area. The outer shell 30 is formed with athroat or annular extension 34 which constitutes the inlet to theimpeller, the inner ends of the ducts communicating therewith. Snuglyenclosing the impeller but permitting the free rotation thereof is aflanged impeller cover 36 secured to the adjacent end of the cylinder 10and to which in turn is secured the flanged end of an inlet branch 36ato the pump. Said branch is annularly recessed to receive an externalflange 37 formed on the throat and also a sealing floating ring 38 whichbears on the flange and also on an annular bearing face on the inletbranch. Said floating ring is prevented frorn rotating by means of anumber of locating dowel pins 39.

Enclosing the end of the shaft between the lrear of the impeller and theadjacent bearing housing is a flanged sealing ring housing 40 bolted tothe internal flange 19 of the cylinder casing. This sealing housingforms an annular chamber 41 surrounding the motor shaft and in which islocated a sleeve 42 secured to the housing 40 against rotation relativethereto by means of a pin 43, but urged axially away from the housing 40by a spring 44. A sealing ring 45, preferably of a synthetic rubber suchas neoprene is mounted around the sleeve 42 and an annular groove 45a toaccommodate the rings 45 is provided in the housing 40. A further sleeve46 is secured for rotation with a clamping ring 47 clamped to the motorshaft, and is spring-urged axially away from the clamping ring 47 bymeans of a spring 48 and thus bears intimately against the rear face ofthe sleeve 42 urged in the contrary direction by the spring 44.

A sealing ring 49, preferably also of a synthetic rubber such asneoprene, is mounted around the motor shaft and is located in an annularrecess in the rear face of sleeve 46.

The sealing ring housing is provided with a radial passage 40a whichcommunicates with a drainolf duct 40b leading from the recess to theexterior.

The discharge member 23 at the discharge end of the pump is providedwith a passage 45 through which pass the leads to the motor.

When the impeller is driven by the motor it draws water through theinlet branch 36a and forces it throughl its rotating spiral ducts 33 tothe inlet ends of the nonrotatable ducts 1S which register therewith.The latter serve to straighten out the ow of liquid which then passesbetween the vanes 17a and then between the vanes 15a in the annular ductin the casing to `the annular discharge passage 23b and then to thedischarge outlet of the coupling member.

Packing glands are not required to prevent the passage of Vliquid to themotor. In pumps as heretofore constructed such packing glands arenecessary. This results in substantial friction if the packing ismaintained tight and if not so maintained there is leakage of airtherethrough and self-priming is lost. In either case there is loss ofeliciency.

In the pump of th'e present `invention no levelling up of pump and motoris necessary, the motor is self-cooled by the liquid being pumped.Output relative to bulk is considerably greater than has heretofore beenthe case and the pump is continuously self-priming after initialpriming.

Should there by any back pressure by leakage between the impeller andits cover, such pressure holds the floating ring 38 in yengagement withthe flange 37 of the impeller and bearing face of the inlet branch 36a.Should there be minus pressure in the inlet side of the pump suchpressure can pass between the ange of the impeller and its seat to drawthe ring into bearing contact with its ange and said bearing face.

Any leakage past the sealing ring housing is conducted to the passage40a in the end of the cylindrical casing and is then drained ot.

What is claimed is:

ll. A centrifugal pump comprising a cylindrical casing constituting thepump body and having an annular axial passage, a wall lat each end ofsaid casing, one said end wall leaving exposed said passage and having acentral aperture, and the other end wall having a series ofcircumferentially-disposed passages communicating with said passage, anelectric motor housed within said casing and between said end walls, theshaft of said motor being disposed along the longitudinal axis of saidcasing and projecting through said end wall aperture, a combined journaland thrust anti-friction bearing carried internally by each said endwall and journalling said shaft, means rendering fluid-tight the motorhousing where penetrated by said shaft, a conical impeller tixedlymounted on the end of said shaft projecting from the motor housing tocommunicate with said casing passage, spiral vanes on said impeller,said vanes forming therebetween ducts each of substantially uniformcross-sectional area throughout its length, spiral vanes in said casingpassage at the impeller adjacent end thereof and forming therebetweenxed spiral ducts at the delivery end of said impeller, an annularextension on said impeller co-axial therewith and projecting therefromin the direction away from said casing, an external peripheral annularflange on said extension, a cover mounted over 'said impeller and havinga central aperture penetrated by said extension which projectstherethrough, said cover having in its casing-remote face andsurrounding said central aperture an yannular recess of greater radiallength than said extension flange, an external peripheral iiange on saidcover, means securing said cover flange to said casing radiallyoutwardly of said casing passage, an inlet branch secured to saidimpeller cover in abutting relation with said casing-remote face of saidcover, the abutting face where confronting said annular recess providinga bearing surface which is recessed to accommodate said extensiontiange, a sealing ring floatingly accommodated in said annular recess,and means preventing rotation -of said sealing ring, whereby saidsealing ring is held to bear on 'said extension flange and said bearingsurface where 4surrounding the latter both by the pressure of liquidwhich may leak Vthereto and by the minus pressure which may exist insaid inlet branch.

2. A centrifugal pump as claimed lin claim l, said means renderingfluid-tight the motor housing where penetrated by said shaft 'comprisingan internal flange on said casing, said apertured end wall being securedto said flange and being recessed inwardly of its aperture to provide anannular chamber surrounding the motor shaft, a sleeve surrounding saidshaft and located in said annular chamber, means securing said sleeveagainst rotation relative to said apertured end wall, means resilientlyurging said sleeve away from said apertured end wall, a sealing ringmounted about said sleeve, the annular wall surface defining saidannular chamber having an annular groove accommodating said sealingring, a second sleeve surrounding the motor shaft inwardly of said flrstmentioned sleeve, means clamping said second sleeve to the motor shaftfor rotation with the latter, means resiliently urging said secondsleeve to bear intimately against the adjacent face of saidfirst-mentioned sleeve, said adjacent face having an annular recess atits minimum diameter, and an annular sealing ring mounted about themotor shaft and located in said latter aunular recess.

References Cited in the tile of this patent UNITED STATES PATENTS1,427,974 Sessions Sept. 5, 1922 2,066,505 Wolfe Ian. 5, 1937 2,406,947Harlamoff Sept. 3, 1946

